The invention relates to the inhibition or destruction of unicellular living organisms such as protozoa, microbes, bacteria, gametes, fungi, yeasts or the like, and viruses. It relates, more especially, to the technical fields of local contraception, of antibiotic therapy, of antisepsis, of combating sexually transmitted diseases including mycoses, and of combating viral conditions, in the context of pharmacy for human or veterinary use or of cosmetics. The invention may also be advantageously applied in the field of the disinfection of surfaces or alternatively in agriculture, for example in combating fungi and bacteria.
Many substances that inhibit or destroy unicellular living organisms are already known, and these include surfactant agents such as quaternary ammonium salts. In particular, it is known that quaternary ammonium halides such as benzalkonium chloride (or dimethylbenzylammonium chloride), alone or in combination with other active principles, are advantageous in these applications (see, for example, British Patent No. 1,554,615, French Patent Nos. 2,431,859, 2,483,177, 2,379,508, 2,384,497, 2,457,641, 2,573,624, 2,418,221, 2,562,888, European Patent Nos. 0,243,713, 0,175,338, 0,132,963, 0,127,131, 0,094,562, 0,076,136, 0,068,399, 0,037,593, unpublished European Patent Application No. 86/402,716.4, filed on 8.12.1986, and international applications WO No. 84/00,877 and WO No. 84/02,649).
It is also known, moreover, that the quaternary ammonium halides which are the easiest to manufacture and the best known, for these applications and in other known applications, are the chlorides, iodides, bromides and chloroiodites (see patents mentioned above, and also French Patent Nos. 2,002,945, 2,185,717, 2,267,092, 2,366,260, 2,366,261, 2,391,991, 2,418,220, 2,419,024, 2,482,090, 2,505,325, 2,517,672, 2,562,799 and European Patent No. 0,191,236).
Moreover, the prior art has already provided many processes for manufacturing these quaternary ammonium salts, but which are directly applicable, among quaternary ammonium halides, only to the chlorites and/or iodides and/or bromides and/or chloroiodites (see above patents and also French Patent Nos. 2,472,558, 2,033,044 and European Patent Nos. 0,094,552 and 0,012,296).
Ammonium fluoride, and processes for preparing and purifying it, are also known (see, for example, French Patent Nos. 2,244,713, 2,253,710 and European Patent No. 0,002,016), as are perfluorinated or polyfluorinated quaternary ammonium salts (for example, French Patent Nos. 2,038,421, 2,051,095, 2,153,489 and European Patent Nos. 0,073,760, 0,100,478, 0,100,477, 0,149,172).
Ionic fluorine is, moreover, well known for its anti caries properties in dental applications (for example, U.S. Pat. No. 4,473,547; VIDAL dictionary, 1985, page 582, O.V.P., Paris, "fluor monal"), optionally combined with a cationic quaternary ammonium compound (see French Patent Nos. 1,486,676 and 1,297,708). In these latter documents, the advantages demonstrated of combining, in one and the same compound, on the one hand fluorine, well known for its anti caries properties, and on the other hand surfactant quaternary ammonium salts, known for their bactericidal properties. However, no genuinely synergistic activity is demonstrated in these applications for dentifrices, with the quaternary ammonium fluorides tested, either with respect to anti caries properties or with respect to bactericidal properties.
French Patent No. 1,297,708 describes, in particular, laurylbenzyldimethylammonium fluoride, a process for preparing this fluoride and its application in a toothpaste. This patent teaches the bactericidal effect of the quaternary ammonium compound and the anti caries effect of the fluorine. However, no synergy is demonstrated between the fluorine and the quaternary ammonium compound.
Finally, Italian Patent No. 1,153,530 describes a process for preparing quaternary ammonium carbonates and then, from these carbonates, quaternary ammonium halides by anion exchange with the corresponding acid, which is stronger than carbonic acid. However, this patent does not mention how this process can be applied to the preparation of fluorides. Moreover, while the compounds obtained by means of this process are suitable for application in the disinfection of surfaces and in industry, they cannot be used directly on human beings or animals, for example in the pharmaceutical compositions in which the compounds must be of high purity.
With respect to this general state of the art, the invention raises the problem of providing a composition that completely inhibits or destroys unicellular living organisms and which is simultaneously applicable to living organisms, human, animal or plant, without thereby causing harmful side effects. In effect, it is difficult, or even impossible, to prepare such a composition at the present time using quaternary ammonium halides without being reconciled either to producing side effects (irritations, allergies, red blotches, etc.) or to being insufficiently active. The problem arises especially with known spermicidal compositions based on benzalkonium chloride, or in combating viruses or retroviruses such as herpes or the LAV, responsible for AIDS.
The invention relates, in particular, to improving the invention which is the subject of unpublished European Patent Application No. 86/402,716.4 and U.S. patent application Ser. No. 07/053 374 filed on May 22 1987 by the applicant.